Exhaust Manifold Bolts

[husker boxster]

I'm hoping to change out the driver's side exhaust manifold today (bad cat). When removing the exhaust manifold bolts going into the engine block, should I...

1) Give 'em the beans and hit them with an impact wrench

or

2) Carefully hand loosen them

I'm really afraid of breaking them off so I'm wondering if either of these approaches is better. I'm leaning towards #1. I've been squirting them with AeroKroil several times over the last 24 hrs in preparation of the extraction.